#list1=[1,2,3,2,6,10,1]

#a=list1[0]

#for i in list1:
#    if i > a:
#        a=i
#print(a)


#list2=[1,2,3,4,'a',1]

# sum=0

#for i in list2:
#    if isinstance(i,int):
#        sum=sum+i
#print(sum)




#x=5
#for i in range(2,x):
#    if x % i ==0:
#        print('不是素数')
#        break
#else:
#    print('是素数')


x = 10
sum=0
for i in range(2,x+1):
    for j in range(2,i):
        if i % j ==0:
            break
    else:
        sum = sum + 1
print(sum)
